Wound retractor

ABSTRACT

An incrementally adjustable wound retractor (100), having a first ring (102) with a diameter greater than the desired diameter of the wound incision. A second ring (104), having an annular axis and a diameter greater than the desired diameter of the wound incision. A flexible sleeve (106), disposed in a generally cylindrical form between the first and second rings (102, 104), the second ring may be rolled over itself and around the annular axis to provide a sleeve with a radical retraction force sufficient to stretch the incision to the desired diameter

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.10/516,198, which entered the National Phase under 35 U.S.C. §371 onNov. 30, 2004 from International Application No. PCT/US2003/017389,filed Jun. 3, 2003, which was published in English on Dec. 18, 2003 asWO 03/103548 A1, now U.S. Pat. No. 7,650,887, issued Jan. 26, 2010,which claims the benefit of U.S. Application No 60/386,159, filed onJun. 5, 2002, and U.S. Application No. 60/415,351, filed on Oct. 2,2002, the disclosures all of which are fully incorporated herein byreference.

BACKGROUND

1. Technical Field

This invention generally relates to medical devices and, morespecifically, to an improved wound retractor providing ease ofincremental retraction and alignment to fit a wide range of incisionsizes, including audible and tactile feedback to the user

2. Description of the Related Art

Surgery typically involves making an incision large enough toaccommodate a surgeon's hand and/or multiple instruments. The incisionmust be kept clean since it is susceptible to infection if touched bydiseased body parts and/or contaminated instruments. As such, woundprotectors are available to insure that exposed sides of an incision arecovered and protected from contaminants. A common deficiency of woundprotectors is their lack of ease of retraction adjustability andstability. U.S. Pat. Nos. 5,524,644 and 6,382,211, both to Crook,attempt to address this deficiency with a wound protector including anouter ring having an oblate cross-section and opposed flat surfaces thatallegedly provide retraction adjustability and stability. The oblatedesign of the outer ring of Crook, however, provides only limitedincremental retraction and can be difficult to twist or turn Inaddition, the Crook design does not provide for an audible feedback tothe user. Accordingly, there is a need in the art for an improved woundretractor that can be easily retracted to fit a wide range of incisionsizes. The improved wound retractor preferably provides audible and/ortactile feedback to the user during retraction.

SUMMARY OF THE INVENTION

An incrementally adjustable wound retractor for sealing edges of asurgical incision and forming an opening in a patient's body cavity, thewound retractor comprising an inner ring, an outer ring and a flexiblesleeve connecting the inner ring and the outer ring. The wound retractorprovides a path for a surgeon to insert his hand and/or instrumentsthrough the opening formed by the wound retractor. The wound retractoris incrementally adjustable to fit a wide range of incision sizes. Thewound retractor is installed or placed in a body cavity such that theinner and outer rings expand around inner and outer edges of theincision Any portion of the flexible sleeve extending outside theincision can be easily rolled onto the outer ring to tightly seal thesides of the wound. The outer ring is preferably shaped to provideaudible and/or tactile feedback to the user In particular, the outerring includes surfaces that are easy to grip and turn to allow the userto manually turn the outer ring and roll up the flexible sleeve withease. The outer ring may be solid or include a lumen with a rod placedtherein to provide audible signal to the user as the outer ring isturned.

These and other features and advantages of the invention will becomemore apparent with a discussion of preferred embodiments in reference tothe associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cutaway side view and an isometric view of anincrementally adjustable wound retractor in accordance with anembodiment of the invention;

FIGS. 2A-2D illustrate the retraction of the outer ring of the woundretractor of FIG. 1 to fit a desired incision;

FIG. 3 is a longitudinal cross-section view of the wound retractor ofFIG. 1 taken along line A-A;

FIG. 4 illustrates the wound retractor of FIG. 1 installed in anincision;

FIG. 5 is a cross-section view of a hollow tube of an outer ring of awound retractor in accordance with a second embodiment of the invention;

FIG. 6 is a cross-section view of an inner rod of the outer ring of thewound retractor in accordance with the second embodiment of theinvention;

FIG. 7 illustrates a cutaway side view of an incrementally adjustablewound retractor in accordance with the second embodiment of theinvention;

FIG. 8 illustrates the retraction and alignment of the outer ring to fita desired incision size in accordance with the second embodiment of theinvention;

FIG. 9 illustrates the wound retractor of FIG. 7 installed in anincision;

FIG. 10 illustrates a longitudinal cross-section view of an outer ringincluding a wire in accordance with a third embodiment of the invention;

FIGS. 11 and 12 illustrate the rolling of the outer ring to fit adesired incision size in accordance with the third embodiment of theinvention;

FIG. 13 is a three-dimensional cross-section view of the wound retractorof FIG. 10;

FIG. 14 is a three-dimensional image of the hollow tube of the outerring of the wound retractor in accordance with the second embodiment ofthe invention;

FIG. 15 is a three-dimensional image of the inner rod of the outer ringof the wound retractor in accordance with the second embodiment of theinvention;

FIG. 16 is a cross-section view of the hollow tube and inner rodcoaxially joined in accordance with the second embodiment of theinvention;

FIGS. 17A-17E illustrate cross-section views of additional embodimentsof the outer ring of the invention;

FIGS. 18A-18L illustrate cross-section views of additional embodimentsof the hollow tube and inner rod of the outer ring of the invention;

FIGS. 19A-19G illustrate cross-section views of additional embodimentsof the outer ring of the invention having generally prolatecross-sections;

FIGS. 20A-20G illustrate cross-section views of additional embodimentsof the outer ring of the invention having generally prolatecross-sections and including lumens;

FIGS. 21A-21E illustrate cross-section views of additional embodimentsof the outer ring of the invention having generally oblatecross-sections;

FIGS. 22A-22E illustrate cross-section views of additional embodimentsof the outer ring of the invention having generally oblatecross-sections and including lumens;

FIG. 23A illustrates a cross-section view of another embodiment of theouter ring of the invention having a triangular cross-section;

FIG. 23B illustrates a cross-section view of the outer ring of FIG. 23Afurther including a lumen;

FIG. 24A illustrates a cross-section view of another embodiment of theouter ring of the invention having a cross-section comprising an oddnumber of sides such as a pentagon;

FIG. 24B illustrates a cross-section view of the outer ring of FIG. 24Afurther including a lumen;

FIGS. 25A-25B illustrate different processes of forming the outer ringof the invention;

FIG. 26 illustrates an axial cross-section view of a surgical accessdevice with a slightly modified gel cap and/or abdominal base inaccordance with another embodiment of the invention;

FIG. 27 is an axial cross-section view of a surgical access device inaccordance with another embodiment of the invention;

FIGS. 28-30 illustrate additional exemplary embodiments of the inventionhaving modifications that could be made to the gel cap and/or theabdominal base so that the surgical access device can be used with thewound retractor;

FIG. 31 illustrates a perspective view of a base of a surgical accessdevice in accordance with another embodiment of the invention;

FIG. 32 is an axial cross-section view of the embodiment illustrated inFIG. 31;

FIGS. 33 and 34 illustrate a base of a surgical access device inaccordance with another embodiment of the invention having at least onetoggle or latch adapted to fit a corresponding cap ring; and

FIGS. 35 and 36 illustrate a base of a surgical access device inaccordance with another embodiment of the invention having a raised wallon an inner diameter and adapted to fit a corresponding cap ring.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

FIG. 1 illustrates a wound retractor 100 in accordance with a firstembodiment of the invention. The wound retractor 100 comprises adouble-tube outer ring 102, an inner ring 104, and a distensible sleeve106 connecting the outer ring 102 and the inner ring 104. The sleeve 106may be attached to the outer ring 102 and the inner ling 104 by heatseal or adhesive. The outer ring 102 and the inner ring 104 arepreferably made of a material of sufficient hardness to retain theirshape after twisting and rolling of the rings. That is, the materialmust be compliant enough to allow the outer ring 102 to be turned aroundits annular axis as further described below and illustrated in FIGS.2A-2D. The shape of the outer ring 102 affects both its ability to gripand to provide stability during and after adjustment. The sleeve 106 ispreferably made of a material that is flexible and impermeable to fluidsand bacteria. The double-tube outer ring 102 preferably comprises afirst circular tube 108 and a second circular tube 110 joined togetherby a small web 112 Each of the circular tubes 108 and 110 may be solidor include a lumen.

FIGS. 2A-2D illustrate the retraction and adjustment of the outer ring102 to fit an incision in accordance with the invention, the woundretractor 100 is axially adjustable in increments In particular, theupper end of the sleeve 106 can be wrapped around the outer ring 102 soas to tightly seal the sides or edges of the incision. The unique shapeof the outer ring 102 provides for an easy snap action when rolled aboutitself. The outer ring 102 also provides for incremental shortening ofthe sleeve 106 and for stability after installation. FIG. 3 illustratesa longitudinal cross-section view of the wound retractor 100 taken alongline A-A.

FIG. 4 illustrates a process of installing the wound retractor 100 in awound opening 400 An incision in the shape of a slit is first made in apatient's body, e.g., the abdominal wall. The inner ring 104 and thesleeve 106 are then manually inserted into body cavity 402 through theincision with the outer ring 102 remaining external to the body cavity402 Once the inner ring 104 is within the body cavity 402, it expandsaround the inner surface of the incision so as to be generally parallelto the abdominal wall. The sleeve 106 provides a channel from theoutside to the inside of the body cavity 402. The outer ring 102initially rests above the abdominal wall around the wound opening 400.Since the upper end of the sleeve 106 is connected to the outer ring102, the sleeve 106 can be drawn upwards and radially outward or inward,thereby drawing the inner ring 104 tightly against the inner surface ofthe abdominal wall. Moreover, the intermediate portion of the sleeve 106is drawn tightly against the sides and edges of the wound opening 400,thereby retracting the adjacent tissue and producing a tightly sealedopening in the body cavity 402. That is, the sleeve 106 contacts theentire wound surface and protectively covers the same and seals it fromcontamination and infection. Depending on the size and depth of theincision, the user can roll up the sleeve 106 by gripping thedouble-tube outer ring 102 and turning it in a direction 200 asillustrated in FIGS. 2A-2C until the sleeve 106 abuts the outer edge ofthe wound opening 400. It should be appreciated that the outer ring 102can be turned around its annular axis in either an outward or inwarddirection to roll the sleeve 106.

The outer ring 102 has a unique and novel double-tube configurationwherein through simple manipulation of forcing a first tube in a firstdirection and a second tube in a second direction, the positions of thefirst and second tubes can be inverted resulting in fast and easyturning of the tubes as illustrated in FIGS. 2A 2D. In one embodiment ofthe invention, the outer ring 102 is rotated by pushing the bottom tubeor second circular tube 110 inward while pulling the top tube or firstcircular tube 108 outward (see FIG. 2A). The combination of the abovesteps results in inversion of the first and second circular tubes asillustrated in FIG. 2D That is, the outer ring 102 can be rotated in180° turns thereby retracting the sleeve 106. The above process can berepeated until a desired compression or wound opening is achieved.

An advantage of the invention is it provides for an easier, faster andhigher retraction rate than that known in the prior art, therebyresulting in less traumatic effects to the patient. Another advantage ofthe invention is it provides tactile gripping and incremental rolling ofthe sleeve about the outer ring. In the above description, the first andsecond tubes of the outer ring are in a vertical position but it shouldbe appreciated that the first and second tubes may be in differentpositions relative to one another such as a horizontal position.

In another embodiment of the invention, a small wire 302 such as astainless steel wire is placed inside a lumen of the double-tube outerring 102 (see FIGS. 3 and 10-13) so as to provide an audible signal asthe outer ring 102 is turned That is, as the double-tube outer ring 102is turned, the wire 302 deflects against the tubing wall so as toprovide an audible sound feedback to the user. Another feature of thewire 302 is it provides retraction stability to the wound retractor 100.

After surgery, the wound retractor 100 may be retrieved by grabbing theinner ring 104 and the sleeve 106 and pulling them through the woundopening 400. The use of the sleeve 106 and the ease of retracting theouter ring 102 provide higher compression between the inner and outerrings. As a result, the wound retractor 100 of the invention providesincremental adjustability to fit a wide range of incision sizes andisolates and protects the wound from bacterial infection as the diseasedbody parts and contaminated instruments are passed through the wound.

FIGS. 5-9 and 14-16 illustrate a wound retractor 500 having a rollerdesign in accordance with another embodiment of the invention. The woundretractor 500 comprises an outer ring 502, an inner ring 504, and adistensible sleeve 506 connecting the outer ring 502 and the inner ring504. The sleeve 506 can be attached to the outer ring 502 and the innerring 504 by heat seal or adhesive The outer ring 502 includes a hollowtube or lumen 508 that has a fan-like shape cross-section as illustratedin FIG. 5. The outer ring 502 further comprises an inner rod 510 thathas a similar fan-like geometry on its outer surface as illustrated inFIG. 6. The hollow tube 508 and the inner rod 510 are coaxially joinedto form the outer ring 502 of the wound retractor 500.

The fan-like geometry of the outer ring 502 serves as an incrementalrotating mechanism In particular, when the hollow tube 508 is manuallyrolled out of its coaxial alignment with respect to the inner rod 510,the hollow tube 508 will index itself until it matches the nextalignment point of the inner rod 510 as illustrated in FIG. 8. When thehollow tube 508 and the inner rod 510 are coaxially aligned, they lockin place preventing further indexing until the steps of retracting arerepeated. It is appreciated that each of the hollow tube 508 and theinner rod 510 has at least one alignment point providing indexing andincremental rotation of the outer ring 502. That is, the outer ring 502can incrementally retract in steps based on the number of alignmentpoints or indexes on the fan.

FIG. 9 illustrates a process of installing the wound retractor 500 in awound opening 900 An incision in the shape of a slit is first made in apatient's body, e.g., the abdominal wall. The inner ling 504 and thesleeve 506 are then manually inserted and positioned underneath andalong the edges of body cavity wall 512, and the outer ring 502 ispulled through the wound opening 900 so as to be placed outside the bodycavity wall 512. Retraction of the sleeve 506 can then be achieved byrolling the outer ring 502 over the sleeve 506 in a direction 700 asshown in FIG. 7 until a desired compression or wound opening isachieved. Incremental retraction is achieved by manually rolling thehollow tube 508 out of its coaxial alignment with the inner rod 510,i.e., the hollow tube 508 can be rolled and indexed to match the nextalignment point between the hollow tube 508 and the inner rod 510

When the hollow tube 508 and the inner rod 510 are coaxially aligned,they lock in place preventing further indexing until the outer ring 502is rolled out of its alignment again. This process is repeated until adesired retraction is achieved. Once surgery is complete, the woundretractor 500 can be retrieved by grabbing the inner ring 504 and thesleeve 506 and pulling them through the wound opening 900.

It is appreciated that the outer ring can be designed in various shapesand sizes to achieve various retraction rates and/or to conform withdifferent body surfaces as illustrated in FIGS. 17A-17E For example, theouter ring may comprise a single or multiple tubes of different shapesand sizes. The single or multiple tubes may be solid or include lumensof different shapes and sizes

Similarly, the wound retractor having the roller design could be ofvarious geometries. As illustrated in FIGS. 18A-18L, hollow tubes 508a-508 l and inner rods 510 a-510 l, respectively, of the outer ring mayhave different shapes and sizes and may contain multiple lockingmechanisms. For example, the inner rods 510 b-510 e and 510 l have solidrectangular cross-sections. In comparison, the inner rods 510 f-510 khave hollow circular cross-sections. The hollow tubes and inner rods maybe made of the same or different materials (e g., soft and/or hard) Forexample, the inner rods may be rigid such as a wire or piece of metal,or they may be flexible such as an extension spring. The lumens of thehollow tubes 508 a-508 l may have cross-sections of different geometriessuch as fan-like geometry, circular, oval, circular with lumps,triangular, rectangular, any geometric shape with multiple sides, etc.Advantages of the above embodiments of the invention include improvedretraction adjustability and stability.

FIGS. 19A-19G illustrate cross-section views of additional embodimentsof the outer ring of the invention having generally prolatecross-sections. That is, the longer axis of the cross-section of theouter ring is generally parallel to axis E-E as illustrated in FIG. 19AThe outer ring can be turned around the axis E-E in either an outward orinward direction 800 to roll up the sleeve (not shown). The outer ringsof FIGS. 19A-19G provide tactile gripping and incremental rolling of thesleeve about the rings FIG. 19B illustrates an outer ring 190 having twostraight chordal surfaces 190 a and 190 b that are generally parallel tothe axis E-E. FIG. 19C illustrates an outer ring having two straightchordal surfaces and two curved chordal surfaces FIGS. 19D-19Gillustrate outer rings having at least two curved chordal surfaces.

FIGS. 20A-20G illustrate cross-section views of the outer rings of FIGS.19A-19G, respectively, further including at least one lumen in eachring. The lumen may house an inner rod (not shown) that deflects againstthe lumen wall providing an audible feedback to the user. The lumen andinner rod may be of different geometries and sizes.

FIGS. 21A-21E illustrate cross-section views of additional embodimentsof the outer ring of the invention having generally oblatecross-sections. That is, the longer axis of the cross-section of theouter ring is generally perpendicular to axis G-G as illustrated in FIG.21A. The outer ring can be turned around the axis G-G in either anoutward or inward direction 900 to roll up the sleeve (not shown). Theouter rings of FIGS. 21A-21E provide tactile gripping and incrementalrolling of the sleeve about the rings. FIGS. 21B-21E illustrate outerrings having at least two curved chordal surfaces

FIGS. 22A-22E illustrate cross-section views of the outer rings of FIGS.21A-21E, respectively, further including at least one lumen in eachring. The lumen may house an inner rod (not shown) that deflects againstthe lumen wall providing an audible feedback to the user. The lumen andinner rod may be of different geometries and sizes.

FIG. 23A illustrates a cross-section view of another embodiment of theouter ring of the invention having a triangular cross-section, and FIG.23B illustrates a cross-section view of the outer ring of FIG. 23Afurther including a lumen. In another embodiment or the invention, FIG.24A illustrates a cross-section view or the outer ring or the inventionhaving an odd number of sides such as a pentagon, and FIG. 24Billustrates a cross-section view of the outer ring of FIG. 24A furtherincluding a lumen. These outer rings provide tactile gripping andincremental rolling of the sleeve about the rings. The lumens of theouter rings in FIGS. 23B and 24B may be of different shapes and sizes tohouse inner rods (not shown) having different shapes and sizes. It isappreciated that the outer ring can be designed in various shapes andsizes to achieve various retraction rates and/or to conform withdifferent body shapes.

FIGS. 25A-25B illustrate different processes of forming the outer ringof the invention. The outer ring, which may be solid or include a lumen,may be molded as a circular ring as shown in FIG. 25A, or the outer ringmay be formed by joining a single or multiple extruded tubes into acircular ring as shown in FIG. 25B.

In another embodiment of the invention, access into and out of apatient's body is achieved by a hand assisted laparoscopic (HAL)procedure using a surgical access device such as the Gelport™ device asdescribed in applicant's international application PCT/US01/29682, filedon Sep. 21, 2001, entitled “Surgical Access Apparatus and Method,” whichis incorporated herein by reference, while retraction is provided by thewound retractor of the present invention The purpose of this embodimentis to combine the features and advantages of both the wound retractor ofthe present invention and the surgical access device as described in thePCT application. As explained in the PCT application, the currentsurgical access device uses a polyisoprene sheath that is wrappeddistally around an O-ring, and once placed into a wound incision, thesheath is then stretched over extended tabs onto an abdominal base Thesheath of the surgical access device requires stretching and often timesrequires multiple attempts to secure it to the abdominal base. A noveltyof this embodiment is to modify the cap and/or the abdominal base of thesurgical access device so that it will accept the wound retractor of thepresent invention to replace the polyisoprene sheath and to maintain anairtight seal. The use of the wound retractor would simplify the HALprocedure and would not require stretching.

Referring to FIG. 26, there is shown a surgical access device 1000 withslight or moderate modifications to a gel cap 1010 and to an abdominalbase 1020. The gel cap 1010 further includes a gel pad 1030 and acircumferential cap ring 1040, which can be inserted and molded to thepad 1030. The resulting gel cap 1010 forms a seal with the base 1020,thereby defining a working channel through the pad 1030, the cap ring1040, the base 1020, and the sleeve 106 of the wound retractor In thismanner, the working channel includes a single valve formed by the gelpad 1030 which provides both a zero seal and an instrument seal for awide range of instrument diameters. Referring to FIG. 27, thecross-section view of gel cap 1010 a illustrates an annular void 1042 athat is formed on the inner circumference of cap ring 1040 a This voidis of particular advantage in forming a sealing relationship with base1020 a. FIGS. 28-30 illustrate additional exemplary embodiments of theinvention having modifications that could be made to the gel cap and/orthe abdominal base so that the surgical access device can be used withthe wound retractor.

FIG. 31 illustrates a perspective view of a base 1020 e in accordancewith another embodiment of the invention. FIG. 32 is an axialcross-section view of the embodiment illustrated in FIG. 31 From theseviews, it will be noted that the base 1020 e can be provided with asmooth generally cylindrical inner surface 1022 e which extendsproximally to a rounded end surface 1024 e and outwardly from the endsurface 1024 e along an annular lip 1026 e, which is sized andconfigured to fit into an annular void formed on the inner circumferenceof a corresponding cap ring. Proximally of the inner surface 1022 e, thebase 1020 e can also include a rounded end surface 1028 e along itsinner diameter for securing the outer ring of the wound retractor oncethe sleeve has been shortened

In another embodiment of the invention, FIGS. 33 and 34 illustrate abase 1020 f having a smooth generally cylindrical inner surface 1022 f,a rounded end surface 1024 f, an annular lip 1026 f, and an end surface1028 f having at least one toggle or latch 1029 f sized and configuredto it a corresponding cap ring. In this embodiment, the toggle or latch1029 f operates to change the inner diameter of the cap ring to create aseal or release the cap ring from the base. In yet another embodiment ofthe invention, FIGS. 35 and 36 illustrate a base 1020 g having a smoothgenerally cylindrical inner surface 1022 g, a rounded end surface 1024g, an annular lip 1026 g, and an end surface 1028 g having a raised wallsized and configured to fit a corresponding cap ring.

An advantage associated with the modified surgical access device is itenables a surgeon to quickly retract and protectively line an abdominalwall incision while being able to easily accommodate variations frompatient to patient in the thickness of the abdominal wall In addition,the device effectively seals around the interior and exterior of theincision, and allows a sealing cap to be attached to seal the abdominalcavity and to enable a laparoscopic procedure to be performed.

Many alterations and modifications may be made by those having ordinaryskill in the art without departing from the spirit and scope of theinvention. For these reasons, the above description should not beconstrued as limiting the invention, but should be interpreted as merelyexemplary of preferred embodiments.

While certain embodiments have been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopethereof as defined by the following claims.

1. A surgical access device comprising: a proximal end, a distal end,and an instrument access channel extending from the proximal end to thedistal end; a wound retractor comprising a proximal end and a distalend, an outer ring at the proximal end, a deformable inner ring at thedistal end, and a flexible, tubular sleeve extending from the outer ringto the inner ring; an annular base comprising a central opening; a capcomprising a working channel therethrough, wherein in an operative stateof the access device, the cap is coupled with the annular base, therebycapturing the outer ring of the wound retractor therebetween, and thetubular sleeve of the wound retractor extends through the centralopening of the annular base; and a retractor shield comprising aproximal end, a distal end, an interior, and an exterior, wherein in theoperative state, the proximal end of the retractor shield is proximal tothe proximal end of the wound retractor, and the distal end of theretractor shield extends into the tubular sleeve of the wound retractor,wherein in the operative state, the instrument access channel extendsthrough the working channel of the cap, the interior of the retractorshield, the annular base, the outer ring of the retractor, the tubularsheath of the retractor, and the inner ring of the retractor
 2. Thesurgical access device of claim 1, wherein a distance between the outerring and the inner ring of the wound retractor is adjustable.
 3. Thesurgical access device of claim 2, wherein the outer ring of the woundretractor comprises an annular axis around which the outer ring isrotatable.
 4. The surgical access device of claim 1, wherein the outerring comprises a lumen.
 5. The surgical access device of claim 4,further comprising a wire disposed in the lumen.
 6. The surgical accessdevice of claim 1, wherein the outer ring is substantially circular. 7.The surgical access device of claim 1, wherein the outer ring comprisesa substantially circular cross-section.
 8. The surgical access device ofclaim 1, wherein the outer ring comprises a cross-section comprising alonger axis and a shorter axis.
 9. The surgical access device of claim1, wherein the working channel of the cap comprises an instrument seal.10. The surgical access device of claim 1, wherein the working channelof the cap comprises a zero seal.
 11. The surgical access device ofclaim 1, wherein the cap comprises a circumferential cap ring and a gelpad disposed in the cap ring, and wherein the working channel extendsthrough the gel pad.
 12. The surgical access device of claim 1, whereinthe cap is releasably couplable to the annular base.
 13. The surgicalaccess device of claim 12, wherein the cap latches to the annular basein the operative state.
 14. The surgical access device of claim 1,wherein the cap directly couples to the annular base in the operativestate.
 15. The surgical access device of claim 1, wherein the retractorshield comprises an annular proximal end.
 16. The surgical access deviceof claim 1, wherein the retractor shield comprises a plurality of shieldmembers extending distally from the proximal end.
 17. The surgicalaccess device of claim 1, wherein the retractor shield converges fromthe proximal end to the distal end.
 18. The surgical access device ofclaim 1, wherein the retractor shield is secured to the annular base 19.The surgical access device of claim 1, wherein the retractor shield issecured to the cap.